Begin by seasoning the duck legs generously with salt and pepper. Place in a shallow dish or resealable bag and refrigerate for at least 3 hours.

While the duck is curing, combine fresh orange juice, honey, and soy sauce in a small saucepan. Heat over medium-low heat until the mixture thickens, about 10-15 minutes.

Set your air fryer to preheat at 380°F (193°C) for about 5 minutes.

Arrange the seasoned duck legs in the air fryer basket, skin side up. Cook for approximately 50-60 minutes, turning halfway through.

Peel and chop the celeriac into cubes. Boil in salted water for about 20 minutes until fork-tender. Mash with butter, salt, and pepper to taste.

In a pan, heat oil over medium heat. Add leafy greens and minced garlic, sauté until wilted, about 5-7 minutes.

In a serving dish, create a bed of creamy celeriac mash, place the duck legs on top, arrange the sautéed greens alongside, and drizzle with citrus glaze.